Add method for getting all classifiers with given name from the scope

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/AbstractScopeAdapter.java

@@ -55,6 +55,12 @@ public abstract class AbstractScopeAdapter implements JetScope {
         return getWorkerScope().getClassifier(name);
     }
 
+    @NotNull
+    @Override
+    public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+        return getWorkerScope().getClassifiers(name);
+    }
+
     @NotNull
     @Override
     public Collection<VariableDescriptor> getProperties(@NotNull Name name) {

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/ChainedScope.java

@@ -51,6 +51,12 @@ public class ChainedScope implements JetScope {
         return getFirstMatch(scopeChain, name, CLASSIFIER_DESCRIPTOR_SCOPE_SELECTOR);
     }
 
+    @NotNull
+    @Override
+    public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+        return getFromAllScopes(scopeChain, name, NAMED_CLASSIFIERS_SCOPE_SELECTOR);
+    }
+
     @Override
     public PackageViewDescriptor getPackage(@NotNull Name name) {
         return getFirstMatch(scopeChain, name, PACKAGE_SCOPE_SELECTOR);

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/FilteringScope.java

@@ -66,6 +66,12 @@ public class FilteringScope implements JetScope {
         return filterDescriptor(workerScope.getClassifier(name));
     }
 
+    @NotNull
+    @Override
+    public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+        return Collections2.filter(workerScope.getClassifiers(name), predicate);
+    }
+
     @NotNull
     @Override
     public Collection<VariableDescriptor> getProperties(@NotNull Name name) {

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/JetScope.java

@@ -53,6 +53,10 @@ public interface JetScope {
     @Nullable
     ClassifierDescriptor getClassifier(@NotNull Name name);
 
+    @NotNull
+    @ReadOnly
+    Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name);
+
     @Nullable
     PackageViewDescriptor getPackage(@NotNull Name name);
 

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/JetScopeImpl.java

@@ -34,6 +34,12 @@ public abstract class JetScopeImpl implements JetScope {
         return null;
     }
 
+    @NotNull
+    @Override
+    public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+        return Collections.emptySet();
+    }
+
     @NotNull
     @Override
     public Collection<VariableDescriptor> getProperties(@NotNull Name name) {

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/JetScopeSelectorUtil.java

@@ -112,6 +112,15 @@ public class JetScopeSelectorUtil {
                 }
             };
 
+    public static final ScopeByNameMultiSelector<ClassifierDescriptor> NAMED_CLASSIFIERS_SCOPE_SELECTOR =
+            new ScopeByNameMultiSelector<ClassifierDescriptor>() {
+                @NotNull
+                @Override
+                public Collection<ClassifierDescriptor> get(@NotNull JetScope scope, @NotNull Name name) {
+                    return scope.getClassifiers(name);
+                }
+            };
+
     public static final ScopeDescriptorSelector<DeclarationDescriptor> ALL_DESCRIPTORS_SCOPE_SELECTOR =
             new ScopeDescriptorSelector<DeclarationDescriptor>() {
                 @NotNull

core/descriptors/src/org/jetbrains/jet/lang/resolve/scopes/SubstitutingScope.java

@@ -98,6 +98,12 @@ public class SubstitutingScope implements JetScope {
         return substitute(workerScope.getClassifier(name));
     }
 
+    @NotNull
+    @Override
+    public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+        return substitute(workerScope.getClassifiers(name));
+    }
+
     @NotNull
     @Override
     public Collection<FunctionDescriptor> getFunctions(@NotNull Name name) {

core/descriptors/src/org/jetbrains/jet/lang/types/ErrorUtils.java

@@ -85,6 +85,12 @@ public class ErrorUtils {
             return ERROR_CLASS;
         }
 
+        @NotNull
+        @Override
+        public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+            return ERROR_CLASSIFIER_GROUP;
+        }
+
         @NotNull
         @Override
         public Set<VariableDescriptor> getProperties(@NotNull Name name) {
@@ -161,6 +167,12 @@ public class ErrorUtils {
             throw new IllegalStateException();
         }
 
+        @NotNull
+        @Override
+        public Collection<ClassifierDescriptor> getClassifiers(@NotNull Name name) {
+            throw new IllegalStateException();
+        }
+
         @Nullable
         @Override
         public PackageViewDescriptor getPackage(@NotNull Name name) {
@@ -254,6 +266,7 @@ public class ErrorUtils {
             ERROR_PROPERTY_TYPE,
             CallableMemberDescriptor.Kind.DECLARATION);
     private static final Set<VariableDescriptor> ERROR_PROPERTY_GROUP = Collections.singleton(ERROR_PROPERTY);
+    private static final Set<ClassifierDescriptor> ERROR_CLASSIFIER_GROUP = Collections.<ClassifierDescriptor>singleton(ERROR_CLASS);
 
     @NotNull
     private static SimpleFunctionDescriptor createErrorFunction(@NotNull ErrorScope ownerScope) {